Exploring flowery MnO2/Ag nanocomposite as an efficient solar-light-driven photocatalyst

Abstract

The day-by-day industrial advancements along with urbanization contribute to severe water pollution, which limits the access to clean water for mankind. Herein, we report a simple water bath technique to fabricate flowery MnO₂ nanocomposites (NCs) to be explored as photocatalyst for the degradation of organic pollutants upon irradiation with natural solar light. We have also developed an efficient and facile approach to boost the photocatalytic efficacy of the synthesized flowery MnO₂ NC by loading Ag nanoparticles (NPs) onto its surface, in turn producing MnO₂/Ag NC. A detailed study of the degradation mechanism in the presence of several scavengers, as well as an additional supplementary oxygen source, ascertained the generation of reactive oxygen species during the degradation process. From the photocatalytic experiments, it was observed that the MnO₂/Ag NC demonstrated much higher photocatalytic performance than the pristine MnO₂ NC, which confirmed that loading Ag NPs on the NC surface was an efficient approach to enhancing the photocatalytic activity of MnO₂ nanoflowers. The notable improvement in the photocatalytic efficacy of MnO₂/Ag NC can be accredited to the trapping of photogenerated charge carriers, which in turn enhances the photocatalytic rate by lowering the rate of recombination of the photoproduced excitons. Hence, our study demonstrates an attractive route to fabricate MnO₂/Ag nanocomposites with improved photocatalytic activity than the pristine metal oxide in the field of wastewater treatment under renewable solar light because of their excellent degradation efficacy.